The present disclosure is generally related to creating map tiles for viewing in a map application of a mobile device, and more specifically to compressing road features based on a zoom level of the map.
Many mobile devices (e.g., a smartphone) have a map application that allows a user to view different geographical areas for certain purposes, such as to navigate roads in a certain area, to find out traffic conditions on certain roads, or to find locations of certain stores. A user navigates within the map application to see different areas to zoom out or zoom in to see the map at different resolutions. A user may navigate the map in various ways, such as by using a touch screen. Typically, the mobile device does not already store the map, but instead requests map tiles from a server. The requested map tiles would correspond to the geographic area that the user has selected.
The retrieval of the map tiles by the mobile device is typically limited by bandwidth (e.g., a radio communications connection relative to a Wi-Fi connection) or cost, as data plans often limit the number of bytes of data. Map tiles at a lower zoom (e.g., a virtual camera is farther from the map) will cover more geographic area, but typically store less information per square distance than a map tile at a higher zoom (e.g., a virtual camera is closer to the map). If the virtual camera is very far away or very close, the data size of the map tiles are often not too large. However, the map tiles at certain zoom levels can contain much road information, particularly when a road network of a city is being viewed using middle levels of zoom.
Therefore, it is desirable to provide methods and system for compressing road features into map tiles that are sent to devices for displaying a view of a road network.